SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: jayare92 on April 05, 2015, 08:16:41 PM

Title: Carb tuning
Post by: jayare92 on April 05, 2015, 08:16:41 PM

455 olds and edelbrock performer intake and holley 700cfm. 150 compression.. carb just seems out of it. Can anyone give me some pointers on tuning. Ive been having to start it with starting fluid. And it wont idle when cold at all. I have to keep giving it throttle to keep it running.  Im not realy experienced when it comes to carbs.

Title: Re: Carb tuning
Post by: jayare92 on April 05, 2015, 08:19:37 PM

Timing is good also. Checked with timing gun

Title: Re: Carb tuning
Post by: Flusher on April 05, 2015, 09:27:18 PM

How does it perform when at operating temperature?  Does it have a working choke? You shouldn't really need one in southern California, I haven't since I ditched the Thermoquad on my first car.  Although it might make your ride a little more user-friendly.

Title: Re: Carb tuning
Post by: jet fever on April 05, 2015, 09:58:45 PM

Sounds like it needs a rebuild

Title: Re: Carb tuning
Post by: jayare92 on April 05, 2015, 10:02:41 PM

Seems to perform fine at operating temp. No working choke.

Title: Re: Carb tuning
Post by: JBASHAM on April 05, 2015, 10:07:15 PM

Check for vacuum leaks...


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Title: Re: Carb tuning
Post by: aquaholic72 on April 05, 2015, 10:56:48 PM

Iv had squirters plug up on edelbrocks
And they dont want to start if theyre plugged..no fuel when u pump, no start.
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Title: Re: Carb tuning
Post by: aquaholic72 on April 05, 2015, 11:35:05 PM

Woops missed the holley part. But bad accelorator pump will make it not fire anyways.. no choke will make it run like poo till it has alil temp in it...my boat wont run on its own for about 5 minutes when its stone cold.

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Title: Re: Carb tuning
Post by: crewchief22 on April 06, 2015, 06:05:02 AM

Quote from: jayare92 on April 05, 2015, 08:19:37 PM

Timing is good also. Checked with timing gun

What is the timing set at?  How much initial and how much total?

Is this a new problem? 

What is the history on the carburetor?  I agree, it might just need a rebuild.

Title: Re: Carb tuning
Post by: jayare92 on April 06, 2015, 07:12:39 AM

Its a problem ive had since i got the boat. Dont know much history about the carb. Ive replaced both accelerator pumps also. Im thinking it needs a rebuild also. Ive just never rebuilt a carb myself.

Title: Re: Carb tuning
Post by: SS-201 on April 06, 2015, 11:44:52 PM

Be sure the air bleeds are clear